Method and apparatus for selecting elastic bands for use in orthodontics



United States Patent O METHOD ANI) APPARATUS FOR SELECT- ING ELASTIC BANDS FOR USE 1N OR- THODONTICS Robert Berman, 121 W. Ross St., Wilkes-Barre, Pa. 18702 Filed July 21, 1964, Ser. No. 384,110 5 Claims. (Cl. 3214) This invention relates to orthodontic equipment and procedures, and more particularly relates to the use of elastic bands for the forced movement of teeth Within the human mouth.

It is an accepted orthodontic procedure to employ elastic bands, also known as rubber bands, to move a tooth or teeth whose position in the mouth is for some reason, whether aesthetic or practical, considered misplaced. In carrying out such a procedure, the orthodontic dentist loops the tooth or teeth to be moved (hereinafter termed the misplaced tooth) with a rst end of the elastic band, and secures the second end of the band to some relatively immovable object in the mouth, with the band under tension so as to slowly and over a considerable period of time, move the misplaced tooth or teeth to the desired orientation. It is common practice to employ other teeth l`(hereinafter termed the anchor teeth), situated laterally of the displaced tooth and with intervening teeth to help it maintain its immobile stance, as the aforesaid relatively immovable object. When this is done, a metallic device bearing a hook for receipt of the second end of the elastic band is generally employed on the anchor teeth.

The inter-tooth spacings of course vary from individual to individual, as does the resistance of the misplaced tooth to movement. In other words, mouth structure varies among patients. Consequently, the orthodontist must experiment with various elastic bands in a given patients mouth to arrive at one that is, in his judgment, likely to exert the proper force yon the misplaced tooth. Very often of course, such estimates turn out to be incorrect, either through faulty judgement of mouth structure or through incorrect guessing as to how much pull a given band between two given teeth will exert. This can lead to premature (and thus unnecessary) return visits, overcompensation for the imponderables, and other cliculties that impede expeditious orthodontic practice.

Accordingly, it is a principal object of the present invention to provide means for selecting an elastic band that will exert a chosen force between the misplaced tooth and the anchor object in a variety of mouth structure variations.

Another object of the present invention is to provide such means whereby the re-orientation of misplaced teeth is rendered more certain and less experimental in a given patients mouth.

Another object of the present invention is to provide a new and improved orthodontic equipment and method.

These and other features, objects, and advantages of the invention will be more fully understood upon consideration of the illustrative embodiments of the invention contained in the appended drawings and described in detail hereinbelow.

In the drawings:

FIGURE 1 is a perspective View of a measuring tool in accordance with the invention,

FIGURE 2 is a detailed section view taken along line 2 2 in FIGURE 1,

FIGURE 3 is a perspective detailed view of a portion of the apparatus shown in FIGURE 1,

FIGURE 4 is a chart for use with the apparatus of FIGURE 1,

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FIGURE 5 shows three representative elastic bands according to the invention,

FIGURE 6 shows a combination instrument according to the invention,

FIGURE 7 shows a detail of the apparatus of FIG- URE 6, and

FIGURE 8 is a schematic view of a band according to the invention in place on a misplaced tooth.

Briefly, the present invention provides a measuring instrument having parts adjustable to take the measure of the distance between a misplaced tooth and any of the possible anchor teeth in a variety of mouth structures. The measuring device is provided with indicia that indicate to the user a significant fact relevant to his choice of elastic band to interconnect the misplaced tooth and an anchor tooth. Also provided are a plurality of elastic bands arranged into categories by known contraction forces at known extended distances thereby providing full range of choice of contraction forces and distances. In one form the said measuring instrument provides by a reading of the said indicia a distance measurement which is selective lof a particular category of elastic band depending on desired contraction force. In another form the measuring instrument itself correlates the distance measured thereby with the desired contraction force to provide indicia indicative of correct category of elastic band, by slide rule action.

Referring now to the drawings, in one embodiment a measuring instrument 10 comprises a longitudinally extended shaft 11 having a slidable sleeve portion 12 axially engaged therewith, and a pair of stop members 13 and 14 arranged at spaced intervals thereon. Preferably the stop members 13 and 14 are arranged at the extreme ends of shaft 11 as shown. The shaft 11 has a uniform cross-sectional area so that slidable sleeve 12 may be freely moved along its length, or at least along a Working portion thereof.

As is shown in FIGURE 2 the cross-section 11a of shaft 11 includes a groove 11b adapted to cooperate with sleeve 12 so that sleeve 12 does not rotate axially upon shaft 11. In FIGURE 3 a detail of sleeve 12, shown partially in section, shows a single axial opening 12e adapted to receive shaft 11. Within axial opening 12C is positioned engaging member 12a which is adapted to ride in groove 11b while exerting spring force thereon so as to secure friction positioning of slidable sleeve 12 along the axis of shaft 11. The opposite end of engaging member 12a emerges vertically through sleeve 12 as measuring edge 15. Stop member 13 thus constitutes a fixed measuring edge as well as a stop, and measuring edge 15 being movable is thereby adapted to gauge distance in cooperation with stop member 13. Arranged along at least a portion of the length of shaft 11 are indicia indicative in this embodiment of a rst independent variable constituting the distance between members 13 and 1S as read by the Vcongruence between end 12b of sleeve 12 and the nearest of said indicia. In the illustrated embodiment of the smallest increment is intended to represent 1/s, and the integers signify whole inches.

As is shown in FIGURE 5 a plurality of elastic bands are provided for use with the invention, the bands being arranged into categories by characteristics of contraction force versus extended distance. It is intended in a preferred embodiment that the categories be clearly identified by color coding the elastic bands. Thus, for example, white color on a band would indicate that at certain extended distances certain contraction forces would be exerted by that band, or indeed by any band so color coded. Pink or yellow, etc., coloring on a band would by the same token indicate diierent but known contraction 3k forces at known extended distances from that already mentioned for a white colored band.

For simplicity, only three elastic bands according to the invention are shown in FIGURE 5. The bands 20, 21, and 22 are of slightly different sizes in regard to both thickness and free length. This is done'to illustrate the fact that the bands may be of any appropriate physicalV Vconguration provided that a given band exerts certain known and predictable pulls at certain known extended distances. Band 20 is meant .to represent a white band, While bands 21 and 22 are means to represent pink and yellow bands respectively. The bands could of course all be fabricated of the exact same free length and other dimensions, the diierences in pull-force exerted at a given extended distance then being attributed entirely to the modulus of elasticity of each band. Alternatively, as is shown in FIGURE 5, the bands may be of varying dimensions with or without varying modulus of elasticity. Again therefore, the essential feature is that the bands are arranged intocategories such that a visible indicia (for example color) on each band identities it as to its Vpull versus extended distance characteristics.

The chart of FIGURE 4 indicates one plausible set of values of the second independent variable constituting the contraction forces, arranged against a set of values of the first independent variable constituting the extended distances, Which might be found useful in a typical orthodontic practice. As is shown by the chart a range of contraction forces is possible at any of several common ex-Y tended distances (that is, length of an elastic band when hooked between an anchor tooth and a misplaced tooth). For example at S a choice is offered among a two oz. contraction forces (hereinafter termed pull), a three oz. pull, and a one oz. pull. At BAL a choice is offered between 31/2 oz., 3 oz., 2 oz., and 11/2 oz. pull. In like manner other choices are offered at other extension distances; onY the chart. The left-hand column of the chart indicates a color code which is uniquely associated with la certain pull at a certain extended distance. Thus, for example, if the looseness and other structural aspects of the misplaced tooth would indicate a 21/2 oz. pull is appropriate, and the distance between the misplaced tooth andthe anchor tooth proves to be 7A, then the Chart would indicate that a pink color coded elastic band would be appropriate (this is determined by reading down from 7s" to 21/2 oz., and then reading left until pink is found). To continueV the illustration if structural considerations indicate again that 21/2 oz. of pull is appropriate, and the distance between the misplaced tooth and the anchor tooth proves to be l then a reading of the chart indicates that a yellow color coded elastic' band is appropriate.

In similar manner the orthodontic practitioner may when he measures the appropriate distance between the Ymisplaced and an anchor tooth, select an elastic band (by the color coded process just described) which will exert precisely the pull he believes is required for that particular misplaced tooth. Of course the chart as shown is Vmerely'illustrative, the colors may be changed, the distances and pulls shown on the chart may be changed to suit requirements, the essential feature being that some indicia appears on each category of band which correlates it to a series of pulls at a series of extended distances.

Shown in FIGURE 6 is an alternative embodiment of the measuring device of FIGURE 1. Again a central shaft 11 has end stops 13 and 14, with end stop 13 forming a xed measuring edge. Slidable sleeve 12 again is arranged to slide'along shaft 11 carrying movable measuring edge 15 therewithl'he distance between the displaced tooth and an anchor tooth is, therefore, gauged between members 13 and 15.7However in this embodiment no distance indicia appear along shaft 11 as in the first embodiment.

Instead along they shaft 11 appear indicia correlated toV pull Vforces in ounces, for example. The slidable sleeve V12 is 'modified from that shown in FIGURE 1 so that' a second sleeve opening appears therein, that is to Say, Slidable sleeve 12 is in this embodiment essentially a double or parallel sleeve, as is best shown in FIGURE 7. In the lower sleeve 12d is arranged second shaft 16 having a detent means 12e similar to means 12a for the similar purpose of allowing second shaft 16 to be slidably moved Within sleeve opening 12d against slightfriction force resistance, and without axial rotation therebetween.

Appearing along the length of axial shaft 16 are indicia indicative of categories of elastic bands. For example when the categories are identiiied by color coding, words indicating colors may appear along shaft 16 as at 16a and 1Gb, or dots of the colors themselves may appear therealong. In sleeve 12 along the bore of axial opening 12d appears a window 12f of sufiicient length and height to show a large enough portion of shaft 16 embraced within the bore of opening 12d to show any of the aforesaid indicia of 'shaft 16 which happens to be positioned thereat a given moment.

The dimensions of shaft 11 and shaft 16, as Well as the positioning of indicia 16a16b, etc., on shaft 16Vare arranged so that the example chart of FIGURE 4 is effectually combined with the measuring instrument of FIG- URE 1 by slide rule action such that a distance. between a misplaced tooth and an anchorY tooth may be laid off between measuring edges 13 and 15 and edge 16C of shaft positionings shown in FIGURE 6, a distance of approximately 1" (not indicated by Vany indicia) has been measured between edges 13 and 15' and a desired force of 3 ozs. has been laid off by aligning edge 16C with the indicia on shaft 11 reading 3, meaning 3 ozs., andthe indicia 16h indicating the category of elastic bands denoted by a pink color coding has appeared in window 12f. The meaning of this indication of courseisthat at'the measured distance with the desired pull a pink color coded elastic band will dor the job. The parts of the measuring Y device of FIGURE 6 are of course arranged so that other distances and pulls maybe arranged on the slideV rule so as to indicate in all cases the appropriate elastic K band category indicia (e.g., color code).

In'FIGURE 8 there is shown, in highly diagrammatic fashion, a portion 30 of a jaw, viewed from inside'the oral cavity, and showing two teeth 31 and 32. Only two teeth are shown for diagrammatic simplicity, butY of course intervening and other teeth may be present. The tooth 31 may be deemed to be the misplaced tooth, and encircling it is a wire fixture 33, having a hook portion 34. The tooth 32 may be 'deemed to be an anchor tooth,V and Vencircling it is a Wire fix-ture 35, having a hook portion 36.

Connecting the hook portions 34 and 36 is anV elastic that band 22 has been chosen from among those shown inFIGURE 5, in accordance with theprinciples of the invention, to provide a certain desired pull-force between the teeth at that distance.

InY operation the orthodontist need not be concerned.V when a patient enters his oice as to whether or not the structure of this patients mouth is different from Vother patients, and to what extent it is different. By using the measuring instrument, Vin either of the embodiments shown, he may rapidly -andaccurately gauge the distance between a misplaced tooth such as 31 and an anchor tooth such as 32, or between the misplaced tooth andrany of several potential anchor teeth. In the first embodiment the indicia on the measuring device will be indicative .of distance. The orthodontist must of coursedetermine what he believes to be the appropriate pullrfor'the tooth involved, depending upon the strength of the tissues surrounding the tooth, the placement of the tooth within the jaw, etc., that is to say, he must determine what the appropriate pull power on the tooth should be in order to move it in the manner and at the rate he desires.

Having determined what is the appropriate pull power in his judgment, and knowing the precise distance between the misplaced tooth and the -anchor tooth the user may resort to the chart of FIGURE 4 which will direct him to appropriately categorized and identifiable elastic band which will exert precisely that pull at precisely that distance. Of course, when a variety of potentia-l anchor teeth are involved, the user may contemplate the various possibilities open to him in terms of distances and pulls, including combinations thereof. Alternatively when e-mploying the embodiment of FIGURE 6 the user after having gauged the distance between the misplaced tooth and the anchor tooth by means lof edges i3 and 15, will align edge 16h with what he has determined to be the appropriate pull yas represented by the indicia of shaft 11 of FIGURE 6, and he will read an indicia 16a within window 12f which will again lead him to the correct category of elastic band to provide the intended pull at intended extended distance.

The elastic bands themselves must be manufactured under very high tolerance procedures with precision compounding and the like in order to insure that the quality control is such that all bands of a given category fall within reasonable tolerance limits of designed pull versus extended distance values. Preferably the bands are manufactured from a high quality rubber of known type, having no unsatisfactory physiological or 4aesthetic shortcomings with regard to oral use, and also being suitable from a service standpoint of use within the oral cavity Without undue deleterious Wear.

It will be appreciated that heretofore an orthodontist or other users of elastic bands for the purpose of moving misplaced teeth within the oral cavity resorted to emperical methods of trial and error which often resulted in poor results and in unnecessary caution as reflected by frequent visits to check the progress of the movement of the mis-A placed teeth. With the means of the present invention, the orthodontist or other user is now enabled to precisely and definitely provide the pull he professionally deems to be best and most appropriate upon the misplaced tooth despite the internal geometry of the persons oral cavity. Thus the orthodontist or other user can now with a variety of people precisely specify and apply an elastic band to yield the precise pull force he wants without regard to which tooth is used as the anchor tooth and what its spacing is.

While the invention has been illustrated by certain embodiments, no limitation thereto is to be inferred. Moreover, changes in form and arrangement of the parts may be made without departing from the spirit and scope of the invention.

What is claimed is:

1. Apparatus for gauging the distance between a tooth and another object in the oral cavity and relating the three variables of distance, pull-force, and elastic band category, comprising first shaft means having a fixed distance. measuring point to be held against said tooth, and incidia therealong correlative to either of the pullforce and band category variables; second shaft means slidably connected to said first shaft for parallel relative sliding motion therebetween, having an indexing point thereon for alignment with any of the indicia on said first shaft means, and bearing indicia therealong correlative to the other of said pull-force and Aband category variables; and indicator means slidably arranged with respect to both said shafts, 'bearing a movable distance measuring point to be held against said object to lay out the distance between said tooth and said object along said first shaft between said fixed and movable measuring points, and means on said indicator means for alignment with any of the indicia on said second shaft means.

2. Apparatus for gauging the distance between a tooth and another object in the oral cavity and relating the three variables of distance, pull-force, and elastic band category, comprising first shaft means having a fixed distance measuring point to be held against said tooth, and indicia therealong correlative to pull-force; second shaft means slidably connected to said first shaft for paralle-l relative sliding motion therebetween, having an indexing point thereon for alignment with any of the pull-force indicia on said first shaft means, and bearing indicia therealong correlative to elastic band category; and indicator means slidably arranged with respect to both said shafts, bearing a movable distance measuring point to be held against said object to lay out the distance between said tooth and said object along said first shaft between said fixed and movable points, and means on said indicator means for alignment with any of the band category indicia on said second shaft means.

3. Method for selecting an elastic bond appropriate to exert a selected pull-force between a tooth and another object in the oral cavity comprising providing elastic bands organized into categories by pull-force versus extended length characteristics and bearing indicia indicative of category; determining the distance between said tooth and said another object as a value of a first independent variable; determining the desiredpull-force on said tooth las a value of a second independent variable; determining from said values the category including said values as characteristics thereof; and selecting a band having the v indicia of the determined category.

4. Method for selecting an elastic band appropriate to exert a selected pull-force between a tooth and another object in the oral cavity comprising providing elastic bands organized into categories by pull-force versus extended length characteristics and being color coded by category; measuring the distance between said tooth and said another object as a value of a first independent variable; determining the desired pull-force on said tooth as a value of a second independent variable; indexing said values mutually `against information relating color code to pull-force versus extended length characteristics to determine a color code and thereby a category; and selecting a band having the determined color code.

5. Method for selecting an elastic band appropriate to exert a selected pull-force between a tooth and another object in the loral cavity comprising providing elastic bands organized into categories by pull-force versus extended length characteristics `and being color-coded by category; measuring the distance between said tooth and said another object as a value of a first independent variable; determining the desired pull-force on said tooth as a value of a second independent variable; consulting a table relating color-code to pull-force versus extended length characteristics to determine a color-code and thereby a category; and selecting a band having the determined color code.

References Cited UNITED STATES PATENTS 883,800 4/19084 Harlow 23S-70 1,461,975 7/1-923 lEston et al. 23S-70 2,059,289 11/ 1936 Svensson 23S-70 2,382,064 8/ 1945 Judd 235--70 RICHARD A. GAUDET, Primary Examiner. I. W. HINEY, Assistant Examiner. 

1. APPARATUS FOR GAUGING THE DISTANCE BETWEEN A TOOTH AND ANOTHER OBJECT IN THE ORAL CAVITY AND RELATING THE THREE VARIABLES OF DISTANCE, PULL-FORCE, AND ELASTIC BAND CATEGORY, COMPRISING FIRST SHAFT MEANS HAVING A FIXED DISTANCE MEASURING POINT TO BE HELD AGAINST SAID TOOTH, AND INDICIA THEREALONG CORRELATIVE TO EITHER OF THE PULLFORCE AND BAND CATEGORY VARIABLES; SECOND SHAFT MEANS SLIDABLY CONNECTED TO SAID FIRST SHAFT FOR PARALLEL RELATIVE SLIDING MOTION THEREBETWEEN, HAVING AN INDEXING POINT THEREON FOR ALIGNMENT WITH ANY OF THE INDICIA ON SAID FIRST SHAFT MEANS, AND BEARING INDICIA THEREALONG CORRELATIVE TO THE OTHER OF SAID PULL-FORCE AND BAND CATEGORY VARIABLES; AND INDICATOR MEANS SLIDABLY ARRANGED WITH RESPECT TO BOTH SAID SHAFTS, BEARING A MOVABLE DISTANCE MEASURING POINT TO BE HELD AGAINST SAID OBJECT TO LAY OUT THE DISTANCE BETWEEN SAID TOOTH AND SAID OBJECT ALONG SAID FIRST SHAFT BETWEEN SAID FIXED AND MOVABLE MEASURING POINTS, AND MEANS ON SAID INDICATOR MEANS FOR ALIGNMENT WITH ANY OF THE INDICIA ON SAID SECOND SHAFT MEANS. 